If you look at first image you see a Transistor Test of BC547B/BC557B
where the curves are vertically mirrored.
To show the complementary pair.

Why should we run such tests?
Of the same reason wwe test transistors in real constructions.
To try to see if they are good or not.

Second image shows the Test Circuit I use in MultiSim (Electronic Workbench Multisim 10.0 Portable.rar)
I use 4 controlled source.
2 voltage sources will take the Collector Voltage sweep
and put it to each of NPN and PNP
2 current sources will take Base-Current sweep
and put it to each of NPN and PNP base terminals.

As you can see here I use 1uA/A in current sources.
Later when I run DC Sweep I add 1-20 I do not get 20 Ampere, but 20uA max.

Third image shows the DC Sweep simulation.
The upper is Voltage source.
Here I run from 0 to 3 Volt. As in the BC547B/BC557B in first image.
The second source is the base current source.
I run from 1-20 STEP 2, which gives 10 lines in the diagram for each of BC547/557

Of course I have Tester for Power Devices, like MJL3281/MJL1302.
And here is better to make Current Souce have 1mA/1A.
Of course because power transistors work at higher current than microampere.

I also have tester for MOSFETs. And JFETs.
The same basic princip, but you use a Gate-Voltage source instead of Current.